Hundreds of football fans rioted in Italy yesterday, attacking a police barracks with stones and clubs, after a man was shot dead by a policeman during a clash between supporters.

Waves of protests were triggered across the country, including a group of about 200 fans in Rome who set fire to cars and smashed the windows of the police barracks, raising questions about the world champions' ability to stamp out violence from their domestic fixtures.

The shooting, which police said was accidental, occurred during a fight between Lazio and Juventus fans at a motorway service station near Arezzo in Tuscany. An unnamed policeman, who reportedly shot twice in the air to end the fight, hit and killed Lazio fan Gabriele Sandri, 25, who was sitting in a car.

"It was a tragic error," the Arezzo police chief, Vincenzo Giacobbe, said. "Our agent intervened to prevent the scuffles between two small groups of people ... from degenerating," he said.

When Lazio's game against Inter Milan was subsequently postponed, hundreds of Lazio fans who were in Milan for the match threw stones at a police station in protest, while fans hurled abuse at police as they entered. "They killed my brother," Cristiano Sandri shouted to reporters at the station.

Inter fans also marched in Milan in protest, while a series of protests were staged at minor grounds around the country.

Outside Rome's Olympic stadium, fans threw firecrackers, set up street barricades and clashed with police. About 10 officers were injured, according to Italian news agency Ansa.

As news spread to grounds hosting games in the top league, Serie A, all kick-offs were delayed 10 minutes in tribute to Sandri, while Atalanta's game with AC Milan in the northern city of Bergamo was abandoned seven minutes after kick-off as fans tried to smash down a glass barrier and invade the pitch. Roma's game with Cagliari was also called off. Crowd trouble also affected a third division match in the southern city of Taranto.

The wave of clashes represented the latest episode in a history of violence that has tarnished the reputation of Italian football. The authorities have sought to get to grips with the problem, with tough measures on stadium security that insist on new turnstiles and more trained stewards. Inter Milan fans were even punished with a one-match ban after they hoisted a banner reading "Naples: the sewer of Italy" in a game against Napoli.

But while injuries caused by violence around stadiums had been cut by 80% since last season, fights between fans who were crossing the country to reach grounds has continued. The Lazio fans involved yesterday were travelling to see their team play Inter Milan, while the Juventus fans were en route from Naples to watch Juventus play Parma. It remained unclear whether the confrontation was pre-arranged.

In September, police in Rome held 66 Lazio fans carrying machetes, knives and chains who were preparing to drive north for a game against Atalanta. Sampdoria and Genoa fans fought for an hour before their Genoa derby in the same month.

The reaction by fans of all stripes to the shooting also reflects the deep hostility felt by many "Ultra" supporters not only towards each other, but also to the police. The events recall the Roma-Lazio derby in 2004 when a rumour spread that a police car had run over a child outside the ground. Fans marched on to the pitch and convinced players to abandon the game, despite repeated messages read over the PA by police that the rumour was false.

The Lazio fan shot yesterday was reported to be a DJ and clothes shop owner. Sports minister Giovanna Melandri said: "The death of the young fan is an immense tragedy."

Backstory

Italy may be the football World Cup holders, but its track record on hooliganism leaves something to be desired. In January an official from amateur club Sammartinese was killed when he was caught up in a fight between players and fans. A month later the Italian Football Federation suspended all matches after Filippo Raciti, a policeman, was struck by an explosive device and killed at the Sicily derby between Catania and Palermo. Catania were ordered to play the rest of this season's games behind closed doors. Three Middlesbrough fans were stabbed and 10 others hurt during Uefa cup quarter finals in 2006, while in April dozens of Manchester United fans were injured, 11 sustaining stab wounds at the hands of Ultras fans, and others from being baton-charged by the carabinieri. Four are pursuing a legal case against the police. Violence and racist chanting have disfigured recent games, notably that between Lazio and Dinamo Bucharest after which five Romanians were injured.